In these cases, antifriction agents are added to the material to reduce friction between the particles by giving them a smooth surface. In general, fine powders have poor sliding properties and tend to stick to the funnel surface, so it is necessary to artificially increase the particle size to an optimum value by granulating the material.
Delamination causes a change in the weight of the tablets. In some cases delamination can be prevented by installing a small agitator in the funnel, but a more radical measure is to equalize the particle size by granulating the material. When speaking of the homogeneity of a material, one also means its homogeneity in particle shape. Obviously, particles having different spatial outlines at approximately the same mass will be placed in the matrix nest with different compactness.
This circumstance will also cause variation in the mass of the tablets. Particle shape equalization is achieved by the granulation process. It should be noted that it is quite difficult to achieve homogeneity of granules, so by varying the ratio of fractions of granulate by experimentation, it is possible to establish the optimal composition that meets the best bulkiness and high quality of tablets at a certain pressing pressure.
Mechanical strength. Mechanical strength is determined by the interlocking of the particles. At the beginning of the pressing process, the tablet mass is compacted, the particles are brought closer together and conditions are created for the manifestation of intermolecular and electrostatic interaction forces.

Intermolecular interaction forces are manifested when the particles approach each other at a distance of 10″6-10″7 cm. The pressing process of the tablet mass can be divided into three stages. The mechanical strength depends on the amount of pressure in the pressing process and it is important to trace the pressure increase during pressing. In impact tablet machines (eccentric) the pressure builds up sharply, as a result of which the surface of the tablet under the impact of the punches is strongly heated (mechanical energy is converted into thermal energy) and the substances fuse to form a continuous cementitious layer.
In rotary tabletting machines, the pressure builds up gradually, which gives better results, as it provides a longer exposure of the tabletting mass to pressure. The longer the exposure, the more completely the air will be removed from the tabletting mass, which after the pressure is removed, expanding, can have a destructive effect on the tablets. In addition, the heating of the tablet near the surface is significantly weakened, which eliminates the harmful effect of increased temperature on the substances that make up the tablet.
Application of high pressure during pressing can adversely affect the quality of tablets and contribute to the wear of tablet machines. High pressure can be compensated by addition of substances possessing a large dipole moment and providing adhesion of particles at relatively low pressures.
Water, having sufficient dipole moment, is a “bridge” between these particles. Water will prevent the binding of particles of difficult to dissolve and insoluble drugs.